THE ACID OPEN-HEARTH PROCESS. 189 moved. This fact holds good whether the recarburizer is added in the furnace or in the ladle. The fear of non-homogeneity under the practice of adding the ferro in the ladle is not entirely unfounded when small heats are made and the metal is not hot, but when charges of 20 to 50 tons of hot steel are properly poured and recarburized, the steel is uniform. When metal is made high in manganese, certain precautions must be taken; but in ordinary structural steels, when the manganese runs below .65 per cent., there is an all-pervading action throughout the melted mass which dispels all thought of non-homogeneity.